class-utils

What is class-utils?

The class-utils npm package provides utilities for working with ES6 classes and prototype functions. It includes methods for adding static and prototype methods, implementing mixins, and other class-related utilities.

What are class-utils's main functionalities?

Adding static methods

This feature allows you to add static methods to a class. The code sample demonstrates adding a static method called 'staticMethod' to 'MyClass' using class-utils.

const cu = require('class-utils');
class MyClass {}
cu.static(MyClass, { staticMethod: function() { return 'Static method'; } });
console.log(MyClass.staticMethod());

Adding prototype methods

This feature enables the addition of prototype methods to a class. The example shows how to add an instance method called 'instanceMethod' to 'MyClass' using class-utils.

const cu = require('class-utils');
class MyClass {}
cu.proto(MyClass, { instanceMethod: function() { return 'Instance method'; } });
let obj = new MyClass();
console.log(obj.instanceMethod());

Implementing mixins

This feature supports the implementation of mixins to extend class functionalities. The code sample illustrates adding a mixin method called 'mixinMethod' to 'MyClass' using a mixin function.

const cu = require('class-utils');
function mixin(source) { source.mixinMethod = function() { return 'Mixin method'; }; }
class MyClass {}
cu.mixin(MyClass, mixin);
let obj = new MyClass();
console.log(obj.mixinMethod());

Other packages similar to class-utils

core-decorators

core-decorators offer decorators for classes and properties, similar to class-utils but using the decorator pattern. It provides a more modern syntax and is often preferred in environments that support decorators.

mixin-decorator

mixin-decorator is similar to class-utils in providing mixin functionalities but does so using ES7 decorators, which can be more intuitive and less verbose for developers familiar with the decorator pattern.

README

class-utils

Utils for working with JavaScript classes and prototype methods.

Please consider following this project's author, Jon Schlinkert, and consider starring the project to show your :heart: and support.

Install

Install with npm:

$ npm install --save class-utils

Usage

var cu = require('class-utils');

API

.has

Returns true if an array has any of the given elements, or an object has any of the give keys.

Params

• obj {Object}
• val {String|Array}
• returns {Boolean}

Example

cu.has(['a', 'b', 'c'], 'c');
//=> true

cu.has(['a', 'b', 'c'], ['c', 'z']);
//=> true

cu.has({a: 'b', c: 'd'}, ['c', 'z']);
//=> true

.hasAll

Returns true if an array or object has all of the given values.

Params

• val {Object|Array}
• values {String|Array}
• returns {Boolean}

Example

cu.hasAll(['a', 'b', 'c'], 'c');
//=> true

cu.hasAll(['a', 'b', 'c'], ['c', 'z']);
//=> false

cu.hasAll({a: 'b', c: 'd'}, ['c', 'z']);
//=> false

.arrayify

Cast the given value to an array.

Params

• val {String|Array}
• returns {Array}

Example

cu.arrayify('foo');
//=> ['foo']

cu.arrayify(['foo']);
//=> ['foo']

.hasConstructor

Returns true if a value has a contructor

Params

• value {Object}
• returns {Boolean}

Example

cu.hasConstructor({});
//=> true

cu.hasConstructor(Object.create(null));
//=> false

.nativeKeys

Get the native ownPropertyNames from the constructor of the given object. An empty array is returned if the object does not have a constructor.

Params

• obj {Object}: Object that has a constructor.
• returns {Array}: Array of keys.

Example

cu.nativeKeys({a: 'b', b: 'c', c: 'd'})
//=> ['a', 'b', 'c']

cu.nativeKeys(function(){})
//=> ['length', 'caller']

.getDescriptor

Returns property descriptor key if it's an "own" property of the given object.

Params

• obj {Object}
• key {String}
• returns {Object}: Returns descriptor key

Example

function App() {}
Object.defineProperty(App.prototype, 'count', {
  get: function() {
    return Object.keys(this).length;
  }
});
cu.getDescriptor(App.prototype, 'count');
// returns:
// {
//   get: [Function],
//   set: undefined,
//   enumerable: false,
//   configurable: false
// }

.copyDescriptor

Copy a descriptor from one object to another.

Params

• receiver {Object}
• provider {Object}
• name {String}
• returns {Object}

Example

function App() {}
Object.defineProperty(App.prototype, 'count', {
  get: function() {
    return Object.keys(this).length;
  }
});
var obj = {};
cu.copyDescriptor(obj, App.prototype, 'count');

.copy

Copy static properties, prototype properties, and descriptors from one object to another.

Params

• receiver {Object}
• provider {Object}
• omit {String|Array}: One or more properties to omit
• returns {Object}

.inherit

Inherit the static properties, prototype properties, and descriptors from of an object.

Params

• receiver {Object}
• provider {Object}
• omit {String|Array}: One or more properties to omit
• returns {Object}

.extend

Returns a function for extending the static properties, prototype properties, and descriptors from the Parent constructor onto Child constructors.

Params

• Parent {Function}: Parent ctor
• extend {Function}: Optional extend function to handle custom extensions. Useful when updating methods that require a specific prototype.
• Child {Function}: Child ctor
• proto {Object}: Optionally pass additional prototype properties to inherit.
• returns {Object}

Example

var extend = cu.extend(Parent);
Parent.extend(Child);

// optional methods
Parent.extend(Child, {
  foo: function() {},
  bar: function() {}
});

.bubble

Bubble up events emitted from static methods on the Parent ctor.

Params

• Parent {Object}
• events {Array}: Event names to bubble up

About

Contributing

Pull requests and stars are always welcome. For bugs and feature requests, please create an issue.

Running Tests

Running and reviewing unit tests is a great way to get familiarized with a library and its API. You can install dependencies and run tests with the following command:

$ npm install && npm test

Building docs

(This project's readme.md is generated by verb, please don't edit the readme directly. Any changes to the readme must be made in the .verb.md readme template.)

To generate the readme, run the following command:

$ npm install -g verbose/verb#dev verb-generate-readme && verb

Related projects

You might also be interested in these projects:

• define-property: Define a non-enumerable property on an object. Uses Reflect.defineProperty when available, otherwise Object.defineProperty. | homepage
• delegate-properties: Deep-clone properties from one object to another and make them non-enumerable, or make existing properties… more | homepage
• is-descriptor: Returns true if a value has the characteristics of a valid JavaScript descriptor. Works for… more | homepage

Contributors

Commits	Contributor
34	jonschlinkert
8	doowb
2	wtgtybhertgeghgtwtg

Author

Jon Schlinkert

• linkedin/in/jonschlinkert
• github/jonschlinkert
• twitter/jonschlinkert

License

Copyright © 2018, Jon Schlinkert. Released under the MIT License.

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This file was generated by verb-generate-readme, v0.6.0, on January 11, 2018.